The present invention relates to an image forming apparatus including a main body and a cover member which are pivotally supported on each other at their one end for pivotal movement relative to each other, and an optical scanning device held by the cover member.
An electrophotographic image forming apparatus includes an optical scanning device and an image forming section. Laser light emitted from the optical scanning device is applied onto an electrostatic latent image bearing member incorporated in the image forming section and the resulting electrostatic latent image is subjected to an electrophotographic process for forming an image on a recording sheet.
Preferably, such an image forming apparatus is easily openable to expose the interior thereof so that the image forming section and like sections can be subjected to maintenance. On the other hand, the image forming apparatus has to prevent laser light from leaking out during the maintenance because the laser light is narrowed down to form a very small spot and hence has high energy.
In attempt to satisfy such requirements, a known image forming apparatus, as described in Japanese Patent Laid-Open Publication No. HEI6-305185 for example, includes a main body and a cover member which are coupled to each other at their one end for pivotal movement relative to each other, and a shutter member disposed on the optical path of laser light so as to be movable up and down, wherein when the cover member is closed, a projection presses up the shutter member to open the optical path, whereas when the cover member is opened, the projection retracts to cause the shutter member to move down by its own weight thereby to close the optical path.
With the image forming apparatus described in Japanese Patent Laid-Open Publication No. HEI6-305185, however, the projection provided on the main body passes through a through-hole provided in the cover member along an arcuate locus as the main body and the cover member pivot relative to each other about their one end and, therefore, the projection and the through-hole have to define a clearance therebetween. For this reason, the clearance defined between the projection and the through-hole may allow dust to pass therethrough and enter the inside of the optical scanning device.
Accordingly, a feature of the present invention is to provide an image forming apparatus capable of preventing dust from entering the inside of an optical scanning device provided with a shutter member which is displaceable between an optical path closing position and an optical path opening position.